Grazing management can improve soil health; how to use annuals to convert perennial grazing lands

CM-MR-2-Graze1by Karl H. Kazaks
Maximizing productivity and profitability by managing for soil health can help livestock producers with perennial grazing lands just as it helps crop producers, said North Carolina State Extension Beef Specialist Dr. Matt Poore, in a recent NRCS-hosted webinar.
That’s particularly true in the Piedmont regions of the mid-Atlantic, Poore said, where the clay-based soils are often very low in nutrients. In areas without poultry production, it’s difficult, given the cost of fertilizer, to invest much in added nutrients. By adopting just a modest approach to rotational grazing — not mob grazing, but moving cows every two or three days — “really poor-quality land can become quite productive,” said Poore.
Piedmont lands “can grow grass very, very well” if producers use managed grazing to improve soil health and water infiltration. Overgrazed pastures typically experience high levels of nutrient and water runoff, which can be detrimental to forage production (and thus livestock production) and shorten stand life. Managed pastures, in contrast, can lead to reduced runoff of water and nutrients, and better cycling of nutrients. More nutrients stay in the pasture system, and producers don’t have to use “nearly as much fertilizer,” while keeping a high level of animal production. Livestock producers are interested in ways to maximize their productivity, Poore said, both because of the current high price of beef as well as recent experiences with drought.
The key to having a successful perennial grazing system, Poore suggested, is to think of pastures as complex ecosystems. By considering the growth requirement of the plants in the pasture, as well as the growth requirements of livestock, producers can develop a management style that meets performance goals while reducing costs and improving the resource base. For example, modifying your approach to winter feeding could yield significant benefits. Farms that continually feed in the same area every winter not only see nutrient deposition concentrated around those areas, but they also see more sediment loss in the spring than farms that rotate the location of their winter feeding areas.
“Unrolling hay is a good way of distributing nutrients,” Poore said, but you want to make sure you’re not wasting hay by unrolling too much. His suggestion: provide free choice hay and unroll an amount of high-quality hay that is less than the cows will need in a day. That way they’ll clean up what you unroll, then get the rest of what they need from the free-choice hay.
Fescuce toxicosis is a problem for livestock producers throughout the mid-Atlantic, and it’s a problem that is creeping northward. Producers have responded by shifting to fall calving, thus putting heifers and calves in cooler conditions during the breeding season.
“But when you have a winter like last winter,” Poore said,” and have to maintain fall calves through a hard winter, fall calving shows its limitations.”
Another tactic producers have taken to deal with toxicosis in all-fescue pastures is moving fertilization to late summer. That provides a more balanced yield, Poore said, “and helps you from having a whole lot of toxic fescue you’ve got to eat up in June and July.”
A long-term solution is in its initial phases: genetic selection for fescue resistance in cattle. In the meantime, though, supplemental feeding is the most direct, if costly, response.
“There’s no question fescue is a major issue that we’ve got to deal with,” Poore said. Producers can’t afford the loss in performance associated with fescues toxicosis. Producers “need heifers to grow and reproduce.” But, he suggested, “there’s got to be a better way to approach this in the long run than using feed.”
Converting toxic fescue stands to non-toxic fescue or warm-season grasses is a longer-term solution producers can take now to address the fescue problem. Such conversions are best undertaken by using annuals to transition betweent the two perennial stands, Poore said.
“It takes time to do these conversions,” he said. Don’t try to convert the entirety of your toxic fescue at once. You may also want to use annuals — warm season followed by cool season — for more than one year. Doing so will help eliminate the toxic fescue as well as break other weed cycles, while also improving soil health.
NRCS’s Ray Archuleta has devised a mix of annuals to use when converting perennial forage ground. The mix, which continues to be modified each year, includes grasses, legumes and brassicas. A typical assortment would include grazing corn, cowpea, sorghum sudangrass, pearl millet, sunflower and radishes. The brassicas, with their deep tap roots, are particularly helpful in scavenging nitrogen deep in the soil and bringing it back to the surface of the soil — nitrogen that in a field with no cover would be leaching down through the soil.
The success of such a transitional annual mix is going to be determined by intial plant population, conditions during establishment and the competitiveness of various species. For example, during last year’s wet summer, one farm using such a mix saw sorghum sudangrass comprise 80 percent of the mature stand, without many legumes. Given the seeding ratio, and the abundant summer water, the sudangrass just outcompeted the other species in the mix.
As for establishing a stand of annuals, results are generally improved by a glyphosate burn-down, though some producers no-till early into existing stands. When it comes to grazing the annual crop, Poore said, “know your goal.” If production is your goal, graze earlier.
Poore is not necessarily an advocate of continually using annuals — it depends on your farm and its goals. For example, last year, due to cold weather, there wasn’t much production from winter annuals that were planted late. Some places even saw erosion on their annual fields from winter rain. He does strongly recommend annuals for converting perennial stands, however.
Whether it’s using annuals to converting perennial forage stands or moving to more managed grazing, the result for livestock producers is similar, Poore said. “It helps you realize there is something to be found here in land that we formerly thought of as poor-quality land.”

2014-08-08T08:00:02+00:00August 8, 2014|Mid Atlantic|0 Comments

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